Long-term neurological sequelae after decompression sickness in retired professional divers.

INTRODUCTION: Decompression sickness (DCS) has traditionally been categorized as type I DCS, affecting joints and skin, and type II affecting the nervous system. In the present study, we wanted to examine whether divers with a history of neurological DCS demonstrated a pattern of symptoms and clinical neurological and neurophysiological signs different from divers with other manifestations of DCS or no history of DCS. METHODS: Up to 1990, 365 Norwegian offshore divers worked in the North Sea. Two hundred and eight divers who had performed saturation diving, bounce diving or both, were included in this study. They filled in a questionnaire for registration of diving experience and health complaints, and episodes of DCS were registered. All participants had a clinical neurological and neurophysiological examination (ERP- P300). RESULTS: One hundred and sixty three of the 208 divers (78.4%) reported episodes of DCS. Neurological DCS was reported by 41 (19.7%) divers. Forty-five divers (21.6%) reported no episodes of DCS. Divers who reported episodes of DCS reported significantly more symptoms compared with divers who reported no DCS. Divers who reported neurological DCS had significantly more neurological findings on motility tests, sensory tests and coordination/cerebellar tests. The P300 motor reaction times were significantly longer in divers reporting DCS, but there was no significant difference between divers with neurological DCS and divers with other forms of DCS. CONCLUSIONS: This study indicates that DCS is associated with long-term effects on the nervous system independent of the symptomatology in the acute stage.

Mortality among professional divers in Norway.

BACKGROUND: Diving operations are technically complex, and the underwater environment poses a high risk of fatal or near miss accidents. Furthermore, long-term effects of diving on bone, the central nervous system and the lung have been observed in divers who have not experienced any diving-related accidents. AIMS: To compare total and cause-specific mortality among Norwegian professional divers by class of diving certificate, relative to the general population. METHODS: Data on mortality were obtained for divers in the Norwegian Inshore Diving Registry, which comprises data on all divers with a certificate valid for professional diving after 1980. By August 2010, 5526 male divers born between 1950 and 1990 were identified, 3130 of whom were fully certified professional divers. The rest of the Norwegian male population born in the same period (1 604 147) served as referents. Data on mortality were obtained by linkage to the Cause of Death Registry. RESULTS: Mortality was 23 per 1000 in professional divers and 24 per 1000 in referents. The hazard ratio was 0.79 (confidence interval [CI] 0.63-0.997). Diving-related accidents and suicide were the most common causes of death among divers. Both were significantly more common among divers with the higher level diving certificates. CONCLUSIONS: Overall, mortality in professional divers was lower than that of the general population. However, professional divers had a higher risk of dying from work-related accident or suicide.

No changes in lung function after a saturation dive to 2.5 MPa with intermittent reduction in Po2 during decompression.

Decompression stress and exposure to hyperoxia may cause a reduction in transfer factor of the lung for carbon monoxide and in maximal aerobic capacity after deep saturation dives. In this study lung function and exercise capacity were assessed before and after a helium-oxygen saturation dive to a pressure of 2.5 MPa where the decompression rate was reduced compared with previous deep dives, and the hyperoxic exposure was reduced by administering oxygen intermittently at pressures of 50 and 30 kPa during decompression. Eight experienced divers of median age 41 years (range 29-48) participated in the dive. The incidence of venous gas microemboli was low compared with previous deep dives. Except for one subject having treatment for decompression sickness, no changes in lung function or angiotensin converting enzyme, a marker of pulmonary endothelial cell damage, were demonstrated. The modified diving procedures with respect to decompression rate and hyperoxic exposure may have contributed to the lack of changes in lung function in this dive compared with previous deep saturation dives.

Electroencephalography and magnetic resonance imaging in neurological decompression sickness.

The purpose of this study was to evaluate the use of electroencephalography (EEG) and magnetic resonance imaging (MRI) in the clinical evaluation of acute decompression sickness (DCS) in the central nervous system (CNS). Twenty-one patients treated because of acute DCS in the CNS during 1999-2001 were included, 15 patients with clinical cerebral DCS and five with clinical spinal cord DCS. Seven patients had abnormalities in their EEG, five with cerebral DCS and two with spinal cord DCS. MRI showed high intensity lesions in the spinal cord in four patients with clinical spinal cord DCS and in one with clinical cerebral DCS. Cerebral lesions were not identified by MRI in any patient. In conclusion, EEG showed unspecific abnormalities in only one third of the cases. Conventional MRI with a 1.5 T scanner may be of help in the diagnosis of DCS in the spinal cord, but not in the brain. EEG and MRI have low sensitivity in the diagnosis of acute DCS in the CNS. Recompression treatment of DCS should still be guided by clinical neurological examination and assessment of symptoms.

MMPI profiles in post-lumbar puncture headache.

From the original material of 300 patients, of whom 37.3% had experienced a post-lumbar puncture headache (PPH), a total of 20 males and 50 females were evaluated with the Minnesota Multiple Personality Inventory (MMPI). The test was administered on average 33 months after the lumbar puncture (range 13-51), at a time when anxiety and depression related to the original investigation for a possible organic neurologic disease were expected to affect the results minimally. In the present material PPH was experienced by 45.7% of the patients, 40% of the males, and 48% of the females. Patients without PPH were used as controls. The selected material was a representative sample of the original material both as to distribution of age, proportion of organic diagnoses, and frequency of PPH. The MMPI disclosed no statistically significant differences between PPH patients and controls regarding personality traits.

Behavioral problems in low-birthweight preschoolers.

Preschool behavior of a population-based sample of 144 5-year-old children with birthweights less than 2000g (LBW) was compared with a random sample of 163 normal-birthweight term controls. The Personality Inventory for Children and the Yale Children's Inventory were completed by the mothers, and child behavior during psychometric testing was assessed. Nineteen per cent of the LBW children compared to 4% of controls had behavioral problems as defined by abnormal scores on more than three behavioral measures. The LBW children were more often socially insecure, anxious and difficult to manage, but inattention and hyperactivity were not prominent. The LBW children were not more sensitive to the negative impact of parental risk factors than normal-birthweight children.

MMPI profiles in migraine before and after biofeedback treatment. Minnesota Multiphasic Personality Inventory.

Migraine has been associated with specific personality traits. Typically, migraine patients show elevation on the "neurotic scales" on the MMPI, and the profiles usually reported can be classified as "psychosomatic". A crucial matter is whether certain personality traits predispose to headache problems or whether they are an effect of such problems. To elucidate this problem, common and classic migraine patients (n = 13) were evaluated with the MMPI before and 2 years after biofeedback treatment. Two subgroups were identified on the basis of degree of clinical improvement. The least improved patients were significantly older and had a significantly longer headache history than the patients showing most improvement. No relationships between age, headache history, and improvement were found within subgroups. Clinical improvement was correlated with significant "normalization" of the MMPI profiles. Thus, personality traits as measured by the MMPI seem to be secondary to headache problems and not a predisposing cause.